PDFF and H∞ Controller Design for PMSM Drive

This paper presents analysis, design and simulation of velocity loop PDFF controllers and H-infinity feedback controller for permanent magnetic synchronous motor (PMSM) in the AC servo system. PDFF and H-infinity control algorithm have its own capability, of achieving good performance criteria such as dynamic reference tracking and load torque disturbance rejection. The PDFF is designed and analyzed in the forward loop to provide low frequency stiffness and overcome low-frequency disturbances like friction. While in the feedback loop, H-infinity controller is designed to meet system robust stability with the existence of external disturbance and model perturbations. The proposed PDFF and H-infinity controllers are designed based on the transfer function of the poly-phase synchronous machine in the synchronous reference frame at field orientation control (FOC). The parameter variations, load changes, and set-point variations of synchronous machine are taking into consideration to study, the dynamic performance.